Gol is a cow, but Katherine Applegate (author of Home of The Brave) also uses her as a symbol. How does Gol represent Kek’s past, present, and possibly his future?
Gol represents the past because, Gol means family. Kek’s family is gone, Gol also represents Kek’s entire old life. How he used to work with cows and cattle.
Gol represents the present because, Gol is very old. And is very lonely as well,
Gol represents the future possibly because, Kek takes Gol to a better place (the zoo) and Kek could possibly go to a better place in the future. They also represent the possible future of the farm. How its going to be sold soon, Gol will most likely die soon as well.
on 
(Book written by Katherine Applegate.)